Astrocytopathy in Balo's disease

Balo concentric sclerosis, an emerging variant of multiple sclerosis: A case-series and literature review

INTRODUCTION

Balo concentric sclerosis (BCS) is a rare demyelinating disease. This study aims to follow up on patients initially diagnosed with BCS and MS or presented with BCS in the context of MS.

METHODS

This study was conducted at an MS clinic center in Isfahan, monitoring 2600 MS patients, among which 10 cases were related to BCS. These 10 patients were assessed clinically and radiologically during 2013-2024, with consecutive MRIs and periodic clinical examinations.

RESULTS

Among the 10 patients, BCS was either the inaugural presentation of MS or occurred in the context of the disease. The most common Symptoms included limb weakness and paresthesia. All patients exhibited characteristic onion-like lesions in the periventricular white matter, with two showing tumefactive demyelination. CSF analysis was abnormal in all patients, revealing positive oligoclonal bands (OCB), which were categorized as type 2 in all patients. Treatment mainly involved rituximab, which indicated plausible results.

CONCLUSION

Our study highlights the variability in BCS clinical presentations and supports its classification as a variant of MS due to overlapping characteristics. Additionally, our findings contribute to understanding BCS's distinct clinical and radiologic profiles and emphasize the importance of further investigation into its pathophysiology and treatment.

A Rare Case of Balo Concentric Sclerosis, a Subtype of Tumefactive Multiple Sclerosis, in a 40-Year-Old Male: Case Report

Balo concentric sclerosis (BCS) is a rare sub-variant of multiple sclerosis (MS), a demyelinating disease affecting the CNS. BCS is considered a disease of the brain's white matter with a characteristic tumefactive ring signified with alternating myelinated and demyelinated layers, which gives it an "onion-ring" appearance. Our patient is a 40-year-old male with a past medical history (PMH) of human papillomavirus (HPV) who presented to the hospital with acute onset of progressive horizontal diplopia in the left eye and mild right-sided facial weakness and sensation of heaviness in the head. After ruling out stroke, the patient's clinical presentation prompted further investigation with MRI, MR spectroscopy, and an oligoclonal bands' panel. MRI imaging showed a concentric bullseye area of T1 low signal intensity in the left parietal lobe with surrounding edema vasogenic ring enhancement. MR spectroscopy showed a sequence of incomplete ring-enhancing lesions demonstrating a lactate peak and increased choline. The oligoclonal bands' panel, which revealed negative oligoclonal bands, had elevated IgG in the CSF. The patient was diagnosed with BCS based on the clinical presentation, MRI, MR spectroscopy, and oligoclonal bands' panel findings. The patient was started on high doses of methylprednisolone, which improved his symptoms within 24-48 hours of the initial dose.

Immunopathology of Tumefactive Demyelinating Lesions-From Idiopathic to Drug-Related Cases

Tumefactive demyelinating lesions (TDL) represent a diagnostic dilemma for clinicians, and in rare atypical cases a collaboration of a neuroradiologist, a neurologist, and a neuropathologist is warranted for accurate diagnosis. Recent advances in neuropathology have shown that TDL represent an umbrella under which many different diagnostic entities can be responsible. TDL can emerge not only as part of the spectrum of classic multiple sclerosis (MS) but also can represent an idiopathic monophasic disease, a relapsing disease with recurrent TDL, or could be part of the myelin oligodendrocyte glycoprotein (MOG)- and aquaporin-4 (AQP4)-associated disease. TDL can appear during the MS disease course, and increasingly cases arise showing an association with specific drug interventions. Although TDL share common features with classic MS lesions, they display some unique features, such as extensive and widespread demyelination, massive and intense parenchymal infiltration by macrophages along with lymphocytes (mainly T but also B cells), dystrophic changes in astrocytes, and the presence of Creutzfeldt cells. This article reviews the existent literature regarding the neuropathological findings of tumefactive demyelination in various disease processes to better facilitate the identification of disease signatures. Recent developments in immunopathology of central nervous system disease suggest that specific pathological immune features (type of demyelination, infiltrating cell type distribution, specific astrocyte pathology and complement deposition) can differentiate tumefactive lesions arising as part of MS, MOG-associated disease, and AQP4 antibody-positive neuromyelitis optica spectrum disorder. Lessons from immunopathology will help us not only stratify these lesions in disease entities but also to better organize treatment strategies. Improved advances in tissue biomarkers should pave the way for prompt and accurate diagnosis of TDL leading to better outcomes for patients.

Diagnosis and Management of Central Nervous System Demyelinating Disorders

The spectrum of demyelinating diseases affecting the central nervous system is broad. Although many have a chronic course, neuroinflammatory conditions often present with acute to subacute onset symptoms requiring hospitalization when severe. This article reviews the acute phase assessment and management of these disorders, with a particular focus on multiple sclerosis, neuromyelitis optica spectrum disorder, myelin oligodendrocyte glycoprotein antibody disorder, and several atypical demyelinating diseases.

Baló's concentric sclerosis - A rare entity within the spectrum of demyelinating diseases

Baló's concentric sclerosis (BCS) is a rare, inflammatory demyelinating disease of the central nervous system (CNS). Historically, BCS was thought to be uniformly fatal and diagnosis was based on postmortem findings. With advances in modern neuroimaging, BCS is currently defined by the presence of concentric layered patterns composed of alternating rings of varying intensity. They are best appreciated on gadolinium-enhanced T1-weighted sequences and predominantly occur in the supratentorial cerebral white matter with sparing of cortical U-fibers. The lamellar pattern of the lesions likely reflects bands of demyelination and relative myelin preservation with minimal axonal loss. While BCS falls within the spectrum of atypical demyelinating diseases, there is ongoing debate over whether BCS is a phenotypical variant of multiple sclerosis (MS) or a separate entity. Corticosteroids comprise first-line therapy but there is ongoing controversy regarding appropriate maintenance therapy. First-line MS disease-modifying therapies such as interferon beta-1a are appropriate for patients who fulfill diagnostic criteria for relapsing-remitting MS. Fingolimod should likely be avoided as Baló-like lesions have been reported during its administration or after withdrawal. Monoclonal antibodies such as natalizumab and rituximab are potentially effective at reducing BCS relapses, but alemtuzumab may be relatively ineffective because humoral immunity does not play a central role in BCS pathogenesis.

Distinct microglial and macrophage distribution patterns in the concentric and lamellar lesions in Baló's disease and neuromyelitis optica spectrum disorders

TMEM119 and purinergic receptor P2Y12 (P2RY12), which are not expressed by recruited peripheral blood macrophages, are proposed to discriminate microglia from macrophages. Therefore, we investigated the distribution patterns of microglia and macrophages in 10 concentric lesions from four autopsied Baló's disease cases and one neuromyelitis optica spectrum disorder (NMOSD) case, using quantitative immunohistochemistry for the markers TMEM119, P2RY12, CD68, CD163 and GLUT5. Three cases with Baló's disease had distal oligodendrogliopathy (DO) showing preferential loss of myelin-associated glycoprotein and early active demyelination in the outermost demyelinating layer (termed DMY-MO). In DMY-MO with DO, TMEM119-positive activated microglia expressing upregulated GLUT5 but markedly downregulated P2RY12 were significantly increased. These activated microglia expressed inducible nitric oxide synthase. Oligodendrocytes and their precursors showed apoptotic-like nuclear condensation in DMY-MO. TMEM119-negative and CD68/CD163-positive macrophages were distributed throughout the lesion center of DMY-MO with DO and these cells demonstrated foamy morphology only in the inner portion but not in the outer portion. In concentric demyelinating lesions from another Baló's case and lamellar demyelinating lesions in an NMOSD case, which had late active demyelination without DO, the densities of TMEM119-, GLUT5- and P2RY12-positive microglia with ramified morphology were significantly increased in myelinated layers but not in demyelinating layers. In particular, in the NMOSD case, TMEM119-positive microglia were confined to the outer portion of the myelinated layers. CD68-positive macrophages with foamy morphology also expressing CD163 accumulated in myelinated as well as in demyelinated layers. These findings suggest that activated microglia expressing TMEM119 and GLUT5, but not P2RY12, are associated with apoptosis of oligodendrocytes in the leading edge of Baló's concentric lesions with DO, whereas TMEM119-, GLUT5- and P2RY12-positive microglia with ramified morphology are associated with myelin preservation in concentric lesions without DO in Baló's disease and NMOSD. These two types of microglia appear to play distinct roles in the formation of concentric lesions.

Multiple Sclerosis: Destruction and Regeneration of Astrocytes in Acute Lesions

There are reports that astrocyte perivascular endfeet are damaged in some cases of multiple sclerosis (MS). This study was designed to determine the origin and outcome of astrocyte damage in acute, resolving, and inactive plaques. Ten acute plaques from 10 early MS cases and 14 plaques of differing histological age from 9 subacute and chronic cases were examined immunohistochemically. Also examined were nonnecrotic early lesions in 3 patients with neuromyelitis optica (NMO). Plaques from 3 MS cases were examined electron microscopically. The edge zones in each of the 10 acute MS lesions revealed a complete loss of astrocyte cell bodies and their pericapillary, perineuronal, and perivascular foot processes. Dendrophagocytosis of degenerate astrocytes was observed. Astrocyte precursors, similar to those that replace destroyed astrocytes in nonnecrotic NMO lesions, were present in areas depleted of astrocytes. Resolving plaques were repopulated initially by stellate astrocytes that stained negatively for the water channel molecule aquaporin4 (AQP4). In older lesions, astrocytes were predominantly AQP4-positive. Loss and recovery of astrocytes in new MS lesions may be as important as myelin loss as a cause of conduction block responsible for symptoms in patients with relapsing and remitting and secondary progressive MS.

Balo’s concentric sclerosis in a patient with spontaneous remission based on magnetic resonance imaging: A case report and review of literature

Balo’s concentric sclerosis (BCS) is a rare monophasic demyelinating disease known as multiple sclerosis subtype and seen as a round lesion with variable hyper and hypo-detoxification layers. Characteristic appearance can be seen as “bulb eye” or “onion bulb”. The initial terminology for this neurological disorder was leukoencephalitis periaxialis concentrica; this is defined as a disease in which the white matter of the brain is destroyed in concentric layers in such a way as to leave the axial cylinders intact. This report presents a case of BCS with spontaneous healing of the patient and a mass lesion with concentric rings adjacent to the left lateral ventricle and the posterior portion of the corpus callosum with peripheral vasogenic edema. The neurological lesion of the patient was similar to the magnetic resonance imaging and clinical findings of the BCS.

7 Tesla MRI of Balo's concentric sclerosis versus multiple sclerosis lesions

Background

Baló's concentric sclerosis (BCS) is a rare condition characterized by concentrically layered white matter lesions. While its pathogenesis is unknown, hypoxia‐induced tissue injury and chemotactic stimuli have been proposed as potential causes of BCS lesion formation. BCS has been suggested to be a variant of multiple sclerosis (MS). Here, we aimed to elucidate similarities and differences between BCS and MS by describing lesion morphology and localization in high‐resolution 7 Tesla (7 T) magnetic resonance imaging (MRI) scans.

Methods

Ten patients with Baló‐type lesions underwent 7 T MRI, and 10 relapsing remitting MS patients served as controls. The 7 T MR imaging protocol included 3D T₁‐weighted (T₁w) magnetization‐prepared rapid gradient echo, 2D high spatial resolution T₂*‐weighted (T₂*w) fast low‐angle shot and susceptibility‐weighted imaging.

Results

Intralesional veins were visible in the center of all but one Baló‐type lesion. Four Baló‐type lesions displayed inhomogeneous intralesional T₂*w signal intensities, which are suggestive of microhemorrhages or small ectatic venules. Eight of 10 BCS patients presented with 97 additional lesions, 36 of which (37%) had a central vein. Lesions involving the cortical gray matter and the U‐fibers were not detected in BCS patients.

Conclusion

Our findings support the hypothesis that BCS and MS share common pathogenetic mechanisms but patients present with different lesion phenotypes.

Balo’s concentric sclerosis: an update and comprehensive literature review

Balo’s concentric sclerosis (BCS) is considered a variant of multiple sclerosis characterized by concentric lamella of alternating demyelinated and partially myelinated tissues. It is a rare and a relatively acute condition. Attacks may proceed rapidly over weeks or months, typically without remission, like Marburg’s variant, resulting in death or severe disability. However, the majority of cases have a more benign, self-limiting course with spontaneous remission. Magnetic resonance imaging is a primary imaging modality in the diagnosis of BCS. Treatment with intense immunosuppression may be indicated in patients with more aggressive form. New reports reveal more evidence regarding the pathophysiology and treatment strategies.

Why Is This Auntminnie a Diagnostic Conundrum?: A Knowledge-Based Approach to Balo's Concentric Sclerosis From Reports of 3 Cases and Pooled Data From 68 Other Patients in the Literature

INTRODUCTION

We came across 3 cases of Balo's concentric sclerosis (BCS). The first of these patients presented to an outside hospital and was transferred to our institution due to complications resulting from a biopsy. The other 2 patients, despite having a characteristic imaging appearance and despite insistence on our part on the diagnosis of BCS, underwent a surgical procedure, which could have been prevented. This led us to review the available literature on BCS.

MATERIAL AND METHODS

A total of 68 patients diagnosed with BCS between 1995 and 2015 were studied and the data collected for the clinical presentation and course, imaging, spinal fluid analysis, treatment, and clinical and imaging outcome.

CONCLUSIONS

A 25% surgery rate (biopsy or resection) was found in the study. We concluded that this relatively high surgery rate in this auntminnie nonsurgical disease is multifactorial; and includes factors like nonfamiliarity with the disease, anxiety on the part of patients and physicians, due to a sometimes rapidly deteriorating clinical picture; and resemblance of the disease with other entities such as tumor and infection. However, characteristic imaging appearance combined with acute or subacute presentation and dramatic improvement in clinical status after high-dose steroid chemotherapy; are highly suggestive of the disease, and can prevent unnecessary surgery.

[Atypical multiple sclerosis - Balo's concentric sclerosis: two case-reports and a review]

This article presents two clinical cases of patients diagnosed with Balo's concentric sclerosis. Distinctive features of the pathogenesis in the aspect of differential diagnosis from other forms of multiple sclerosis and possible treatment are discussed.

Balo's concentric lesions with concurrent features of Schilder's disease in relapsing multiple sclerosis: neuropathological findings

Atypical inflammatory demyelinating syndromes are rare neurological diseases that differ from multiple sclerosis (MS), owing to unusual clinicoradiological and pathological findings, and poor responses to treatment. The distinction between them and the criteria for their diagnoses are poorly defined due to the lack of advanced research studies. Balo's concentric sclerosis (BCS) and Schilder's disease (SD) are two of these syndromes and can present as monophasic or in association with chronic MS. Both variants are difficult to distinguish when they present in acute stages. We describe an autopsy case of middle-aged female with a chronic history of MS newly relapsed with atypical demyelinating lesions, which showed concurrent features of BCS and SD. We also describe the neuropathological findings, and discuss the overlapping features between these two variants.

Exploring the overlap between multiple sclerosis, tumefactive demyelination and Baló's concentric sclerosis

The availability of magnetic resonance imaging (MRI) has led to increasing recognition that multiple sclerosis (MS), tumefactive demyelination (TD) and Baló's concentric sclerosis (BCS) share many overlapping features. Baló-like lesions, which exhibit limited features of BCS, may represent an intermediate between BCS and typical MS demyelination. Lesions labeled as tumefactive are typically larger, but otherwise have much in common with conventional MS lesions, and TD and BCS lesions can also overlap. In this article, we explore the similarities between typical MS, TD and BCS cases, and reflect on the potential insights that intermediate or overlapping phenotypes may contribute towards an understanding of MS immunopathogenesis, and question whether these atypical forms of demyelination should be classified as separate demyelinating diseases, as different lesional manifestations of demyelination of any cause or as part of a spectrum with conventional MS.

[My way to "Keep Pioneering": integrated neuroscience and immunology research produces a paradigm shift for intractable neurological disease]

The motto of Prof. Yoshigoro Kuroiwa, who established the first independent neurology department in Japan at Kyushu University, is "Keep Pioneering". His students have followed this motto in all fields. I hereby present my efforts to keep pioneering in the following fields: (1) multiple sclerosis (MS); (2) central nervous system (CNS) involvement associated with peripheral atopic inflammation; and (3) care network for patients with intractable neurological disease. In MS, I propose that Th1/Th17 cell-mediated connexin astrocytopathy may play a critical role in producing huge demyelinating lesions in MS, neuromyelitis optica (NMO), and Baló's concentric sclerosis. I discovered a peculiar myelitis that occurred in patients with atopic disorders, and designated it atopic myelitis. In this condition, allodynia and neuropathic pain are cardinal features, regardless of the presence or absence of spinal cord MRI lesions. We found that peripheral atopic inflammation in mice produces allodynia as well as activation of microglia and astroglia in the spinal cord. It is important to involve a variety of medical specialists and care coordinators for collaborative work on medical and social care issues for people with intractable disease. The motto of "Keep Pioneering" in neurology covers not only advanced research for the creation of new therapies for intractable neurological disease, but also caring for actual people with intractable disease, which I believe is the corporate social responsibility of our neurological society. I think that "Keep Pioneering" is a challenging process that never ends throughout one's life.

Eccentric development of Balo's concentric sclerosis: detected by magnetic resonance diffusion-weighted imaging and magnetic resonance spectroscopy

BACKGROUND

The concentricity of BCS has captured wide attention; the findings of the current study may provide useful information on the centrifugal pathogenesis of BCS.

OBJECTIVE

This study aims to evaluate the performance of MRI, DWI and MRS in elucidating the pathogenesis of Balo's lesions expanding.

METHODS

Six clinically diagnosed BCS cases were reviewed, and the findings obtained by MRI, DWI and MRS were analyzed. DWI data were available for six patients, with the DWI and ADC imaging locations being central and peripheral layers of the index lesion. At TE 144ms, we calculated metabolite ratios of MRS at different depths of the demyelinating lesions and compared with the lesion on the opposite normal side for two patients.

RESULTS

The ADC values of 18 typical concentric lesions revealed that the central lesion had the highest ADC value, followed by the internal ring, and the outermost layer had the lowest ADC value. The reduction in NAA/Cr and the increase in Cho/Cr were more evident in the central lesion than in the internal and outermost ring.

CONCLUSION

The findings of DWI and MRS indicate Balo's concentric rings develop gradually and centrifugally. Of course, this hypothesis remains to be proved by further experimental studies.

Baló's concentric sclerosis

Baló's concentric sclerosis is often regarded as a rare variant of multiple sclerosis. Patients with this disorder present with acute or subacute neurological deterioration, with MRI showing one or more concentrically multilayered ring-like lesions usually in the cerebral white matter. Historically, Baló's concentric sclerosis was thought fatal in all cases. However, the availability of MRI has led to a better appreciation of the variable natural history of patients presenting with radiologically evident Baló lesions and the clinical association with multiple sclerosis and, less often, with other neurological disorders. Important advances have increased understanding of the immunopathogenic mechanisms associated with the formation of Baló lesions. However, how to treat an acute lesion and when or whether to start treatment are less well understood, although for patients with Baló lesions who also fulfil standard diagnostic criteria for multiple sclerosis, our opinion is that treatment with multiple sclerosis disease-modifying therapy would seem reasonable.

First use of alemtuzumab in Balo's concentric sclerosis: a case report

Balo's concentric sclerosis (BCS) is a rare demyelinating disorder of the central nervous system. The humanised monoclonal antibody alemtuzumab has shown efficacy in another demyelinating disorder, relapsing-remitting multiple sclerosis. We aimed to explore its efficacy in treatment-refractory BCS. A 52-year-old male with radiologically confirmed progressive BCS resistant to steroids, plasmapharesis and cyclophosphamide was administered a standard protocol of alemtuzumab. Treatment failed to slow his decline; he died 6 months after administration. Why alemtuzumab induced no clinical or radiological impact may be multifactorial. We review the evidence directing BCS therapy and propose the next steps for exploring this potentially fatal condition.

Anti-aquaporin-4 antibody-seronegative NMO spectrum disorder with Baló's concentric lesions

A 34-year-old woman developed simultaneous bilateral severe optic neuritis and subsequent myelitis. Two months after the first attack, she developed a headache and dysesthesia in the left arm. Brain magnetic resonance imaging revealed multiple hyperintense lesions in the white matter of the right hemisphere, some of which were Baló-like concentric lesions. Our diagnosis was neuromyelitis optica spectrum disorder with Baló's concentric sclerosis (BCS), although the patient was negative for anti-aquaporin-4 (anti-APQ4) antibodies. Our case suggests that Baló's concentric sclerosis overlaps with neuromyelitis optica spectrum disorder and that this overlapping is caused by a mechanism that does not involve anti-AQP4 antibodies.

Disease-specific therapy of idiopathic inflammatory demyelinating disorders

Central nervous system idiopathic inflammatory demyelinating disorders are a heterogenous group of diseases that share inflammation and demyelination as key features. Although the exact pathophysiology remains to be fully unveiled, these conditions are challenging to clinicians who seek specific therapeutic options for their patients. For two of these conditions, multiple sclerosis and neuromyelitis optica, there are now several possible therapies in an ever-evolving field. This review will touch on the various idiopathic inflammatory demyelinating disorders and discuss the various treatment options currently available.

Extensive loss of connexins in Baló's disease: evidence for an auto-antibody-independent astrocytopathy via impaired astrocyte-oligodendrocyte/myelin interaction

Extensive aquaporin-4 (AQP4) loss without perivascular deposition of either activated complement or immunoglobulins is a characteristic of Baló's disease. Our aim in this study was to investigate the relationship between astrocytopathy and demyelination in Baló's disease, focusing on connexins (Cx), which form gap junctions among glial cells and myelin. Autopsied specimens from four cases that provided seven actively demyelinating concentric lesions infiltrated with numerous CD68(+) macrophages were immunohistochemically examined for the astrocyte markers glial fibrillary acidic protein (GFAP), AQP4, Cx43, Cx30 and megalencephalic leukoencephalopathy with subcortical cyst 1 (MLC1). Specimens were also stained for oligodendrocyte/myelin markers, namely Cx32, Cx47, myelin-associated glycoprotein (MAG), myelin oligodendrocyte glycoprotein (MOG), oligodendrocyte-specific protein (OSP) and Nogo-A. Serum samples from six patients that had undergone magnetic resonance imaging, confirming a diagnosis of Baló's disease, were assayed for the presence of anti-Cx43, -Cx32 and -AQP4 antibodies. Despite the presence of numerous GFAP- and MLC1-positive astrocytes, there was a marked decrease in the levels of Cx43, Cx32 and Cx47. At the leading edges, Cx43 and AQP4 were mostly absent despite positive GFAP, MLC1, Cx32, Cx47, MOG, MAG, and OSP immunoreactivity. Of the six Baló's disease patients, none were positive for anti-Cxs or -AQP4 antibodies. Baló's disease is characterized by extensive loss of Cxs and AQP4, and a lack of auto-antibodies to Cxs and AQP4. Loss of Cx43 and AQP4 in the presence of other oligodendrocyte/myelin proteins at the leading edges suggests the possibility that auto-antibody-independent astrocytopathy may contribute to disease pathology via the disruption of astrocyte-oligodendrocyte/myelin interactions.